Growth hormone (GH) synthesized and secreted by the pituitary gland not only regulates the growth and development of the body, but also plays an important regulatory role in many metabolic disorders. The biological function of GH is that it is activated. Binding surface receptor (GHR). ), based on molecular biology to construct various GHR gene knockout mouse models is the basis for elucidating the GH regulatory mechanism? Cre? LoxP recombinase system is mouse systemic or tissue specific (liver), skeletal muscle, fat , Macrophages, pancreatic islets, etc.) β cells, etc.) knock out the ghr gene, and study the interaction between GH/GHR signals and other signal pathways? Mouse model GH/GHR related signaling pathways?